The present invention relates to a high switching speed semiconductor device more particularly the present invention relates to a semiconductor device having a small leakage current and exhibiting a good pulse response, and a method for manufacturing the same.
In the prior art, in order to shorten a recovery time of a semiconductor device having a pn junction to improve a pulse response, it has been proposed to dope an impurity (lifetime killer) such as gold or platinum for reducing a lifetime of minority carriers in the semiconductor device. For example, U.S. Pat. No. 3,067,485 discloses a high switching speed semiconductor diode having Au or Pt uniformly doped to a saturation level into a substrate. When the lifetime killer is doped, a reverse recovery time of the pn junction is reduced. Unfortunately, a leakage current in a reverse blocking state increases with such doping.